Burner



2 Sheets-.Sheet l BURNER J. E. GREENAWALT Filed Feb. 9,

April 5, 193s.

April 5, 1938.

" J. E. GREENAWALT BURNER Filed Feb. 9, 1934 2 Sheets-Sheet 2 HTroe/VEKPatented Apr. 5, 1938 UNITED STATES- PATENT oFFlcE I BURNER John E.Greenawalt, New York, N. Y.A n Application February 9, 1934, Serial No.710,397

claims.

' My invention has relation to improvements in burners particularlyadapted for the burning of liquid fuel, such as oil, -and it consists inthe novel features of construction more fully set forth in 5 thespecication and pointed out in the claims.

The present invention is an improving departure from my co-pendingapplication Serial No. 685,820, filed August 19, 1933, and as in saidapplication the essential features of the invention are directed to themeans for carbureting and distributing the fuel over a wide area so'that combustion may be complete and productive of intense heat.

Among the objects of the invention are the l5 following: the provisionof a burner embodying a fuel distributing head for subdividing the fuelintoA minute particles and mixing air with said minute fuel particlesbefore they are discharged from the distributing head to obtain not onlya thorough atomization but also partial vaporization of the fuel; theprovision of a secondary supply of air on both sides of the surfacesfrom which the mixed air and fuel discharge to insure ample air tosupport the combustion of the fuel; the forceful ejecting of the mixedair and fuel from the oriiices of the distributing head to preventcombustion within the head; the protection of the burner against theheat of the combustion chamber by the provision of a suitable shieldheld in spaced relation with said head, and the provision of means forcirculating air through such space to keep down the temperature of theshield, thus protecting the distributing head and pro- 4longing'the lifeof the shield; the arrangement of the fuel discharge ports to expeditereception of the fuel and eil'ect a radial discharge thereof to expelthe mixed fuel and air from the distributing head before ignitionthereof; and such other objects and advantages as are inherent in theinvention and which will become more apparent from a detaileddescription of the invention in @connection with the accompanyingdrawings, in iff'whichi l Y Figure 1 is a side elevation of my improved@i5 burner mounted for operation in connection with a down draftfurnace, a part of which is shown in longitudinal section; Fig. 2 is amiddle vertical longitudinal section through the burner and that partvof the furnace immediately adjacent the 7,

burner; Fi'g. '3 is a plan view of a portion of the furnace showing theannular air-,control damper for regulating the air supply to thefurnace; Fig. 4 is a horizontal cross-section taken on a plane indicatedby the line 4-4 of Fig. 2; Fig. 5 is a horizontal cross-section takenthrough the fuel` distributing head on a plane indicated by the line f 55 of Fig. 2; Fig. 6is a bottom plan of a fragment of the distributinghead disk 2; and Fig. 7 is a cross-sectional detail taken through thefurnace damper on the line 'If-'I of Fig. 3.

Referring to the drawings, B represents my improved burner positioned inthe opening O in the roof R of the down draft furnace F, the fueldistributing head I of the burner projecting into combustion chamber C.The burner B is carried by a suitable housing H which is supported byanges f, f on what may be termed a wall box W positioned in the openingO and resting on the furnace roof R. The fuel distributing head Icomprises a circular disk 2, at the center of which .is a perforatedboss 3 in -which is securely fixed a tube 4 which extends upwardlytherefrom and is rotatably mounted within a bearing member 5 supportedfrom the top 6 of the housing H. The bearing member comprises an uppercylindrical section 1 and a lower section 1', and in the upper sectionare ball bearings 8 and 8 in spaced relation which take both thevertical and lateral thrust of the tube 4 when the latter is rotated, aspresently to appear. A fuel receiving chamber 9 is formed around theboss 3 of disk 2 by an annular member IIJ having a flanged portion IIand a central frusta-conical portion I2 which encircles the boss 3 andthe lower part of tube 4. 'I'he boss 3 is shouldered at the upper partof its inner surface so as to provide an oil well I3 around the tube 4,into which the fuel oil is discharged from a feed pipe I4 within thehousing H and connected with a pipe I5 passing out of the housing to asuitable source of fuel supply (not shown). A series of bosses I6 extendentirely around and inwardly from the periphery of the disk 2 on theupper surface thereof, and a series' of bosses II extend entirely aroundand inwardly from the periphery of the lower surface of the disk 2, andthe iiange II of the member Ill is securely bolted against the bosses I6while a circular plate or shield I8 (slightly conoidal) is boltedagainst the bosses Il. A single s et of bolts I9, uniformly spaced,secure all three of these distributing head members in intimatelyassembled relation. The bosses I6 are shaped to provide angular passagesor ports 2li between them. The inner parts a of the ports communicatingwith the chamber 9 approach tangency to the vWall I2 of the chamber 9,and the outer parts b of the ports are radially disposed with respect tothe periphery of the distributing head I. The bosses Il which serve tohold the plate I8 in spaced relation with disk 2 are4 shaped similarlyto the bosses I6, and, of course, the passage-ways 2I between saidbosses would be shaped similar to the passage-ways or ports 20. Thereason for shaping the passage-ways will presently appear.

On the upper surface 22 of flange II are a plurality of radiallydisposed ribs or vanes 23 which serve as fan blades for drawing air tothe periphery of the distributing head I when the burner is inoperation. An air-gate or damper 24 is provided in the wall of housing Hand is equipped with a notched rack 25 pivotally mounted on a pin 26near the lower end of the gate 24 so that it may engage a lip 21projecting from flange j to hold the gate in any one of a series of openpositions for controlling the amount of air admitted into the housing H.As explained above, the fuel distributing head is rotatably supported bythe bearing member and is adapted to be rapidly rotated by means of amotor M to s shaft 28 of which tube 4 'is directly connected by means ofa coupling comprising members 29 and 30 secured together in spacedrelation by means of bolts 3| and threaded sleeves 32. The provision ofthe space 33 between the coupling members 29 and 30 permits air to enterthe upper end of tube 4 through which it passes to the inner surface ofplate I8 taking up much of the heat from said plate before dischargingfrom the passage-ways 2| between bosses I1. Ihis circulation of air overthe inner surface of plate I8 thus servesto hold down the temperature ofsaid plate so that it will not be destroyed by the heat of thecombustion chamber.

In order that there may be an adequate supply of air within thecombustion chamber C to maintain combustion of the fuel throughout saidchamber a plurality of a'ir intake openings 34 are provided in the roofR of the furnace F, said openings coinciding with openings 34 in the topplate 35 of the wall box W. An annular damper plate 36 is mounted on theplate 35 above the openings 34', said plate 36 being confined by meansof a series of evenly spaced rollers 31 mounted on studs 38. The plate36 is provided with a plurality of openings 39 of the same size andspacing as the openings 34 so as either to close the openings 34 orentirely open them by the proper rotation of the plate 36 by means of ahandle 46 provided for this purpose. 'Ihe amount of movement of theplate 36 is limited by a pin 4I projecting from the plate 35jinto i aslot 42 at the margin of the plate 36.

It will be observed that the bosses I6 are widened slightly toward theperiphery of disk 2, and the passage-ways b are correspondingly reducedin size toward the periphery. 'I'he purpose of this is to limit thewidth of the oil passages toward the periphery of the disk and therebyobtain a maximum -centrifugal action on the stream and discharge it withsufficient velocity to throw the fuel particles away from the disk andthus prevent ignition of the fuel in the passage-ways. The purpose ofhaving the inner` part a of the passage-ways somewhat' tangential to thewall I2 of the chamber. 9 is to give greater freedom of entry of the oilparticles to the passage-ways as the disk is rapidly revolved in thedirection of the arrow (Fig. 5). However, the passage-ways must not betangential at their outlets because it lis one 'of the objects of theinvention to expel the mixed fuel and air from the distributing head asfar as possible and a tangertial outlet would cause the fuel mixture tohug the periphery of the distributing head. It is for this reason thatthe outer parts b of the passageways are radially disposed with respectto' the distributing head. 'Ihis arrangement also prevents the formationof eddy currents within the distributing head YI whereby the flamesoutside of the head might be drawn into thel head and cause prematurecombustion.

The action of my improved oil burner is as follows. 'I'he oil isdelivered from the pipe I4 into the oil well I3 around the tube .4 fromwhich it is expelledby centrifugal action after which it impinges on theinner conical surfaceof the wall I2 of the receiving chamber 9. Thecentrifugal action causes the oil to spread out over this surface into avery thin film which becomes more atomized as the oil approaches theinside of iiange II where it enters the passage-ways 20 between bossesI6. Of course, air is mixed with the oil as it discharges from the oilwell I3 and when the oil reaches the passage-ways 20 it is furtherbroken up and mixed with air by the fan action of the bosses I6.Obviously, the passage-ways 20 all receive approximately the same amountof oil and air on account of the uniform distribution thereof by thecentrifugal force; and on account of the radial disposition of the outerportions b of the passage-ways 20 and the con-.- stricted outlets of thepassages which serveas nozzles, this fuel 'mixture is ejected underconsiderable force from said passage-ways by the time the oil passesthrough the passages 20 and is about to be discharged therefrom. It isnot only uniformly distributed around the fuel distributing head I, butis also in a very fine state of division, or atomization, so that it maybe very easily and quickly vaporized the instant it enters thecombustion chamber C. In addition to the air that is discharged from thepassages 20 with the oil there are two other supplies of air to insurethorough atomization and combustion at the distributing head. The onesupplyv of air is created by the fan blades 23 projecting upwardly fromthe flange II and enters the combustion chamber C in sheet formimmediately above the fuel mixture. The other air supply is dischargedfrom the passage-ways 2l between disk 2 and plate I8 and enters thecombustion chamber C as a plurality of jets immediately below the fuelmixture issuing from the passage-ways 20. The bosses I'I serve as fanblades to maintain a high velocity circulation of the air throughpassageways 2i. Thus the fuel mixture enters the combustion chamber Cbetween two air supplies so as to insure suillcient air to completelyatomize the fuel and obtain`an effective ignition. Of course, combustionis continued in the combustion chamber and additional air that might beneeded to further the combustion in said chamber'may be obtained byregulating the damper plate 36. Thus there are three air 'supplies forthe fuel, the primary air supply entering the combustion chamber Cintimately mixed with the fuel from the distributing head I, andthesecondary air supply entering the combustion chamber on both sides ofthe spray of mixed fuel and air issuing y from the distributing head I.

I have found in. practice that the amount of primary air shouldwithwhich the secondary air passes into the combustion chamber C isincreased by the vanes 23 on the flange II. The supply of air'enteringthe combustion chamber below the fuel mixture also serves the purpose ofkeeping down the temperature of the plate I8 which serves as aprotecting shield for the burner to prevent the destruction of the samefrom the intense heat of the combustion chamber C.

The high peripheral speed of the distributing head i causes an intenseturbulence in the combustion chamber C. This turbulence expedites themixing of the atomized fuel and the air so that I obtain an explosivemixture almost as soon as the fuel and the air enters the combustionchamber C. Therefore, combustion proceeds immediately and continuouslyas the mixed gases are whirled downwardly through the combustionchamber.

Having described Amy invention, I claim:

1. In a burner for liquid fuel, a fuel distributing head, means forfeeding fuel into the head, fan blades within the head for forcing airtherethrough, an impeller associated with the head, means for rotatingthe distributing head, a disk supported in spaced relation with saiddistributing head to protect the same from the heat of the burning fuel,and means for circulating air in the space between said disk and thehead.

2. In a burner for liquid fuel, a fuel distributorand impeller in thegeneral shape of a disk having a central chamber, said impeller havingan air inlet, a plurality of radially disposed blades circumferentiallyspaced around said central chamber, some of said blades forming fuelpassages between them and other of said blades forming air passagewaysbetween them, a plurality of fan blades on one side of the impeller, adisk on the other side of the impeller to shield the same from the heatof the burning fuel, and means for introducing fuel to said chamber.

3. In a burner for liquid fuel, a fuel distributor and impeller in thegeneral shape of a disk having a central chamber, a plurality ofradially disposed blades circumferentially spaced around said centralchamber, said chamber having an inlet for air, means for introducingfuel into said chamber, said blades forming fuel and air passagesbetween them, a plurality of fan blades on one side of the impeller, adisk on the other side of the impeller and spaced therefrom to shieldthe impeller from the heat of the burning fuel, and a plurality ofradially disposed blades circumferentially spaced between the impellerand said shield disk, said blades extending inwardly from the peripheryof the impeller.

4. In a burner for 4liquid fuel, a fuel distributing head, said headcomprising a hollow disk-like member having an annular chamber and ahollow marginal flange communicating therewith, an annular fuelreservoir within said chamber, means for feeding fuel to said reservoir,the outer wall of said chamber being inclined outwardly and downwardly,and means for rotating said head and the fuel reservoir, to expel thefuel therefrom by centrifugal action.

5. In a burner for liquid fuel, a fuel distributing head, said headcomprising a hollow disk-like member having an annular chamber and ahollow marginal ange communicating therewith, an annular fuel reservoirwithin said chamber, mean for feeding fuel to said reservoir, the outerwall of said reservoir inclining outwardly and upwardly, and the outerwall of said chamber being inclined outwardly and downwardly, and meansfor rotating said head and the fuel reservoir, to expel the fueltherefrom by centrifugal action.

JOHN E. GREENAWALT.

